JP2023074174A - Manufacturing method of fuel battery, manufacturing method of membrane electrode assembly, membrane electrode assembly, composite of membrane electrode assembly and air-permeability base material, and fuel battery - Google Patents

Abstract

To manufacture a film and an electrode assembly of a fuel battery without deformation and with a peripheral edge by coating an electrolyte film thin and deformable even in the air, with an electrode ink carrying an electrolyte solution and a catalyst and made of carbon and water or water and an alcohol system.SOLUTION: A masking base material is laminated in a movement direction of a polymer electrolyte laminated onto a back sheet or an air permeability base material, and a masking base material is set so as to be orthogonal to the movement direction of the polymer electrolyte at the time of a coating start and a coating termination of the electrode on a heating suction roll. Thereby, a peripheral edge of the electrode and a non-coated part are formed by coating an electrode ink thereto.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for manufacturing a membrane-electrode assembly for a PEFC (Polymer Electrolyte membrane Fuel Cell) fuel cell, and a fuel cell manufactured by the method.
More specifically, the present invention relates to a method of forming electrodes on a CCM (Catalyst Coated Membrane) type electrolyte membrane in which electrode ink is directly applied to the electrolyte membrane. The application according to the present invention is not particularly limited, but includes roll coating, slit die (slot nozzle) coating, screen printing, curtain coating, dispensing, inkjet, atomization (including fiberization) application including spraying, electrostatic atomization ( It includes a method of applying particles or fibers to an object to be coated, such as application, and also includes microcurtain application.
Micro curtain is a wide-angle pattern airless spray nozzle, etc., when spraying liquid at a relatively low pressure of around 0.3 MPa. In this method, overspray particles are not generated on the coated surface. When it passes the object to be coated and the distance is increased, it changes into a mist.
In addition, atomization (fibrillation) application is not only atomization by spraying, but also atomization while dispersing liquids containing solid fine particles by ultrasonic waves, spin such as electrospinning, and particleization by centrifugal force of a rotating body. It is applied by fibrizing. It also includes a method of creating particles and fibers by applying the meltblown method to liquids. In the above-mentioned ultrasonic atomization and centrifugal atomization, the directionality of the atomized particles is unstable, so compressed air is used ( air assist) refers to a method of attaching or applying them to an object. In the present invention, these are collectively referred to as sprays below.

Conventionally, an electrolyte solution and a finely powdered catalyst made of platinum supported on carbon particles or carbon fibers are mixed with a solvent and applied as an electrode ink to a GDL (Gas diffusion layer) and pressed against an electrolyte membrane. It was applied to a mold film and transferred to an electrolyte membrane. Since the pressure bonding method and the transfer method do not involve a liquid, a resistance occurs between the electrolyte membrane and the electrode, resulting in deterioration of the performance of the fuel cell. In order to solve this problem, a method has been proposed in which a CCM type electrode catalyst ink is directly applied to the electrolyte membrane.

Patent Document 1 is a CCM method invented by the present inventor, in which a roll-to-roll electrolyte membrane is unwound and adsorbed to a heated adsorption drum (roll) or adsorption belt. In this method, the electrode ink is applied in layers by spraying or the like and then dried. Since the electrolyte membrane is adsorbed and heated by the heating of an adsorption drum or the like, it is laminated as a thin film by spraying or the like, so the spray particles adhere to the electrolyte membrane and the solvent instantly evaporates at the moment of leveling. As a result, the electrolyte is not damaged and the adhesion is enhanced, so that the interfacial resistance between the electrode and the electrolyte membrane can be reduced to the utmost limit, so that an ideal CCM can be formed. In addition, since the electrolyte membrane is sucked by interposing a permeable paper or film wider than the electrolyte membrane between the adsorption drum and the electrolyte, the entire surface of the electrolyte membrane is prevented from leaving any adsorption marks on the porous body such as the adsorption drum. It is ideal because it can be applied while uniformly sucking, but in the case of spraying, the spray particles scatter, so a mask was essential.

Patent document 2 is also a method invented by the present inventor, in which electrode-shaped recesses are formed by bonding films as electrode-shaped masks on both sides of an electrolyte membrane for roll-to-roll. A method is proposed in which the electrode ink is applied in layers while the electrode ink is formed, unwound, and adsorbed by a heated adsorption roll or adsorption belt, and then wound up. This method is ideal because the mask can be aligned with both poles from the beginning, resulting in high productivity. However, due to the structure in which the electrode portion is hollowed out, the unused portion of the hollowed out portion is wasted. For example, if the electrolyte membrane width is 250 mm and the electrode size is a perfect square such as 210 mm × 210 mm, and the uncoated portion (periphery) is as wide as 20 mm or more, there is no problem. The mask base material was elongated in the direction of the rectangle, had a narrow peripheral edge of about 10 mm, and when three electrodes were to be formed, the handling of the mask base itself was unstable and accurate masking could not be performed.

CCM in wet membranes with precise masking, especially with the ideal three-phase structure for water discharge and oxygen uptake, especially for the formation of micropore and mesopore structures at the cathode electrode, especially with pulsed spraying. The industry has longed for an apparatus and method that can automatically manufacture high-performance membrane-electrode assemblies according to the method. The application method is not limited to spraying, and a slot nozzle or the like can also be used in the present invention. When a slot nozzle is used, one or both of the longitudinal and cross mask substrates may not be used in some cases.

JP 2004-351413 JP 2005-63780

The electrolyte membrane is thin, less than 25 microns, or even less than 15 microns. It stretches when pulled, and is extremely delicate and easily deformed even by moisture in the air. It has been required to laminate the electrode ink as a thin film by a spray method, particularly an impact pulse method, on the electrolyte membrane heated and adsorbed by an adsorption roll or the like while instantaneously volatilizing the solvent at the interface of the electrolyte membrane. In addition, an uncoated portion (periphery) of a desired size is required around the electrode for assembly with a separator, gasket, or the like.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a high-quality and durable membrane-electrode assembly (MEA) for a PEFC fuel cell, and a fuel using the MEA. It is to provide batteries.
More specifically, a thin film of electrode ink is applied directly to the roll-to-roll electrolyte membrane, laminated as necessary, and a high-performance membrane/electrode assembly with a peripheral edge where the electrode ink is not applied. is to be manufactured, and by extension, a high-performance fuel cell is to be manufactured.

In the present invention, a long electrolyte membrane laminated on a back sheet or a support substrate is continuously or intermittently unwound by an unwinding device and moved to apply an electrode ink to the electrolyte membrane to form an electrode on the electrolyte membrane. A method for manufacturing a fuel cell membrane-electrode assembly, which is wound by a winding device, wherein a thin and long strip is formed on both sides for forming the edge or peripheral edge of the electrode of the electrolyte membrane from the unwinding step to the coating start position. laminating the first masking base material on the electrolyte membrane; applying the electrode ink with a coating device while heating and adsorbing the electrolyte membrane; drying the electrode ink; and removing the first masking substrate during the process of manufacturing a membrane-electrode assembly for a fuel cell.

The present invention provides a method of manufacturing a membrane-electrode assembly for a fuel cell, wherein a plurality of electrodes are formed on the electrolyte membrane in the width direction of the electrolyte membrane.

In the present invention, there is provided a method for manufacturing membranes and electrodes for fuel cells, characterized in that a second masking substrate is interposed between an electrode pattern application end position and an electrode pattern application start position perpendicular to the moving direction of the electrolyte membrane. offer.

The present invention provides a method for manufacturing a membrane-electrode assembly for a fuel cell, characterized in that an adhesive is applied to at least the side of the first masking substrate which is to be laminated to the electrolyte membrane.

The present invention provides a method for producing a membrane-electrode assembly for a fuel cell, wherein at least the first masking substrate on the electrolyte membrane is preliminarily laminated with the electrolyte membrane via an adhesive and wound up. do.

In the present invention, the adhesive of the first masking substrate contains a slight adhesive, is applied to a position that does not come into contact with the solvent of the electrode ink, and is applied in a porous form or in a plurality of spaced stripes. is less than half the area of the masking base material.

In the present invention, the second masking substrate arranged perpendicular to the moving direction of the electrolyte membrane is movable together with the unwinding and winding device, and when the electrode ink application in the moving direction of the electrolyte membrane is finished and when the coating is started, To provide a method for manufacturing a membrane-electrode assembly for a fuel cell characterized by automatically moving to those positions and masking them.

The present invention uses a membrane-electrode assembly (MEA) in which an anode electrode is formed on one side of a fuel cell electrolyte membrane that moves by roll to roll, and a cathode electrode is formed on the opposite side of the anode electrode. The ultimate goal is to manufacture a fuel cell that Therefore, in the present invention, the first electrode ink is directly applied to the electrolyte membrane on which the back sheet is laminated, dried to form the first electrode, and a breathable sheet such as a support base material is placed on the electrode forming surface. Laminate. In addition, an adhesive that can be peeled off and placed on both sides of the air-permeable sheet at places (edges such as the periphery) that do not interfere with the electrodes on the electrolyte membrane so that the electrolyte membrane on which the electrodes are formed and the laminated air-permeable sheet do not shift. A composite sheet is formed by laminating air-permeable substrates to which an adhesive has been applied. The backsheet may be peeled off at the same time as or after forming the composite sheet. As an example, the step of adsorbing the breathable substrate side of the composite sheet to a heating adsorption roll or a heating adsorption belt; a step of applying a second electrode ink on the electrolyte membrane on the opposite side of the first electrode, and a step of drying the second electrode ink to form a second electrode. A method for manufacturing a membrane-electrode assembly can be provided. Furthermore, in the present invention, a GDL (gas diffusion layer) can be laminated on the manufactured MEA, a gasket or a separator can be set to create a cell, and several hundred sets of cells can be combined to form a fuel cell.

In the present invention, when forming the electrodes, a masking base material can be automatically laminated on the electrolyte membrane in the longitudinal direction to form an uncoated portion (edge) of the electrode in the flow direction of the electrolyte. An adhesive may be applied to said edge of the masking substrate that contacts the electrolyte membrane. In particular, it is possible to apply a weak adhesive that does not easily leave a residue after peeling, or to apply it in a porous form or in the form of thin stripes at intervals in order to reduce the adhesion area. In addition, a second masking base material having an adhesive applied to necessary portions is adhered and laminated on the first masking base material so as to be perpendicular to the first masking base material in the longitudinal direction, and the electrodes are formed. An electrode with a peripheral edge can be formed by forming an electrolyte membrane with a shape mask on the same line as the coating, or by forming it separately, applying an electrode ink on it, and drying it. The masking operation may be performed in the roll-to-roll line for electrode ink application as described above, or may be performed in advance in a separate process.

In the present invention, since a heating adsorption roll can be used, 99% or more of the solvent amount can be volatilized instantaneously, for example, within 3 seconds after the electrode ink applied to the electrolyte membrane by suction has wetted the electrolyte membrane. , which is ideal because the adhesion between the film and the electrode can be enhanced and the interfacial resistance can be lowered. Also, the masking base material can be removed by winding it after the part where the solvent has almost evaporated.

Further, in the present invention, if the impact pulse method, which is a pulsating spray belonging to the spray method and is a method in which speed is added to the spray particles and is a registered trademark of M-Tech Smart Co., Ltd., the adhesion of the catalyst to the electrolyte membrane is improved. further increase.

Furthermore, in the present invention, the amount of electrode ink per square centimeter can be adjusted to 0.001 to 0.15 milligrams by a spray method, particularly an impact pulse method. The amount of coating per layer can be reduced by a combination of a spray method using impact pulses and a heated adsorption drum. and alcohol as a solvent, the non-volatile content of the electrode ink can be reduced to 10% or less by weight. In addition, the solvent of the electrolyte membrane heated to 50 to 80 ° C. is added to the heat conduction to the electrolyte membrane on the heating adsorption drum and the heat amount of 1.5 to 4 kW h for the surface area of 0.5 square meters of the heating adsorption drum. Since the cooling by the heat of vaporization due to the evaporation of is also extremely small, the non-volatile content can be reduced to 5% or less, or even 1% or less.

The advantage of setting the solid content concentration as described above is that the more the layers are made thinner, the more uniform the catalyst layer can be formed. In addition, since thin films can be stacked, the load on the electrolyte membrane is reduced, leading to improved performance of the fuel cell.

Further, in the present invention, the electrolyte membrane is heated at, for example, 50 to 120° C. on the surface of the heating adsorption roll, on which one of the electrodes is formed, via a support substrate, such as an air-permeable substrate, such as a microporous substrate such as dust-free paper. However, since it can be sucked by, for example, a commercially available inexpensive vacuum pump with a degree of vacuum of about 60 to 100 KPa, it is possible to manufacture a defect-free membrane-electrode assembly without damaging the electrolyte membrane on which electrodes are formed on one side. In addition, the method of applying the adhesive to both sides of the air-permeable substrate is intended to prevent slippage before being adsorbed by the heating adsorption roll. The electrolyte membrane can be uniformly adsorbed through the air-permeable substrate. Also, the adhesive can be a weak adhesive that can be easily peeled off in a post-process.

The vacuum pump should be selected from commercially available relatively inexpensive ones, for example, the KRF, KHA, and KHH series of Orion, which can produce a degree of vacuum of about 60 to 100 KPa, which has been used for CCM applications in the fuel cell industry since around 2002.

In the present invention, even if the electrode ink is applied directly to the electrolyte membrane of 25 micrometers or even 15 micrometers or less, which is easily deformed and difficult to handle, by a spray method, a slot nozzle method, or the like, it is possible to apply a thin film for the above reason. A membrane-electrode assembly with stable quality can be manufactured.

As described above, according to the present invention, even if the electrode ink is directly applied to the delicate electrolyte, an ideal membrane-electrode interface can be obtained, and a high-quality electrode-uncoated membrane/electrode with a peripheral edge can be obtained. An electrode assembly can be manufactured and, in turn, a fuel cell can be manufactured using the MEA.

FIG. 4 is a schematic cross-sectional view of a structure in which a masking base material is laminated from above in the movement direction of an electrolyte membrane adsorbed by a heating adsorption roll according to an embodiment of the present invention; 4 is a schematic view of the width direction in which a masking base material is laminated from above in the moving direction of an electrolyte membrane adsorbed by a heating adsorption roll according to an embodiment of the present invention. FIG. 4 is a diagram relating to electrodes and uncoated portions in relation to the moving direction of the electrolytic membrane according to the embodiment of the present invention; FIG. 4 is a schematic cross-sectional view of the arrangement of the masking substrate in the direction perpendicular to the moving direction of the electrolyte membrane adsorbed by the adsorption heating roll according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a masking device provided orthogonal to the moving direction of the electrolyte membrane on the adsorption heating roll according to the embodiment of the present invention; FIG. 6 is a cross-sectional view of an application example of FIG. 5; FIG. 4 is a diagram showing electrodes and peripheral edges formed on an electrolyte membrane according to an embodiment of the present invention; 1 is a schematic cross-sectional view of lamination of a back sheet, an electrolyte membrane, and a masking base material for masking the movement direction of the electrolyte membrane according to an embodiment of the present invention. 1 is a schematic diagram of a support base material (breathable sheet or the like) according to an embodiment of the present invention, an electrolyte membrane having electrodes formed on one side thereof, and a masking base material laminated in the movement direction of the electrolyte membrane. FIG. 2 is a schematic cross-sectional view showing electrodes of both electrodes formed on an electrolyte membrane according to an embodiment of the present invention, leaving an uncoated portion (periphery). FIG. 4 is a layout diagram of three heads according to the embodiment of the present invention; FIG. 4 is a diagram of a spray pattern directly under three heads according to the embodiment of the invention; FIG. 4 is a diagram of a three-head controlled spray application pattern according to an embodiment of the present invention; Fig. 3 is a pulsating spray coating pattern of forward movement by a controlled spray coating pattern of three heads according to an embodiment of the present invention; FIG. 4 is a back-moving pulsating spray coating pattern with a three-head controlled spray coating pattern according to an embodiment of the present invention; FIG. FIG. 10 is a pulsatile spray coating pattern with reciprocating movement in a controlled spray coating pattern of three heads according to an embodiment of the present invention; FIG. FIG. 10 is a continuous spray coating pattern with reciprocating movement in a controlled spray coating pattern of three heads according to an embodiment of the present invention; FIG.

Preferred embodiments of the present invention will be described below with reference to the drawings. It should be noted that the following embodiments are merely examples for facilitating understanding of the invention, and do not include additions, substitutions, modifications, etc. that can be implemented by those skilled in the art within the scope that does not deviate from the technical idea of the invention. isn't it.

The drawings schematically show preferred embodiments of the invention.

In FIG. 1, the electrolyte membrane 2 is unwound from the unwinding device 8, adsorbed by the heating adsorption roll 1, and moved. The movement of the heating adsorption roll may be continuous or intermittent. Before the coating device 5, the masking substrate 3 is guided by the roll 7 to be laminated on the electrolyte membrane, moved together with the electrolyte film on the heating adsorption roll, and the electrode ink is coated on the electrolyte membrane by the coating device 5. - 特許庁If the coating device uses a slot nozzle, the electrode ink can be applied as a liquid film, so it can be applied with almost no adhesion to the masking substrate, and it is also effective in that the electrode pattern can be formed linearly at the start and end of coating, but it is effective because it is laminated with a thin film. An ultrasonic or two-fluid spray head is preferred for this purpose. Application is carried out by spraying with the desired spray stream 6 . The spray pattern width is, for example, a circular pattern, a donut pattern, or an elliptical pattern having a width of 5 mm to 30 mm. It can be layered while applying in pulses so that it does not occur. Also, when sprayed at the same time, the patterns can be arranged so that they do not interfere, and the spray patterns can be overlapped by short traversing of 2.5 to 15 mm.
One or several spray heads can be used to apply a continuous or pulsating spray while traversing the electrolyte membrane perpendicularly. In particular, a small number of spray heads are arranged so that the spray streams do not interfere with each other, and the movement (rotation) of the heating adsorption roll is stopped while traversing (reciprocating) and spray coating. After moving forward and spraying, the heating adsorption roll is moved (rotated) so that the electrode spray pattern on the electrolyte membrane that is sprayed forward and the spray pattern that is sprayed backward over a desired length in the movement direction of the electrolyte membrane overlap. Stop and repeat the spray coating while moving back. When it is desired to apply by moving the electrolyte membrane continuously by the method of applying by traversing with a small number of heads, uniform application is possible by repeating the method of applying by one side movement and not applying by reverse movement. For example, if the total effective pattern of the three heads is 45 mm, it is possible to spray in the forward direction and not to spray in the reverse direction, and advance 45 mm in the time required for the round trip. From the viewpoint of coating efficiency, the forward speed during spraying should be 100 mm/sec or less, and the reverse speed should be doubled to 200 mm/sec or more, which is preferable in terms of productivity.
The place where the masking base material is laminated may be any place between the unwinding section of the unwinding device 8 and the coating position. Also, the coating device and means may be a slot nozzle or the like as described above, and is not limited to spraying.
After the coating is completed, the masking base material may be removed at a desired position by, for example, winding it up. The removal of the masking base material may be performed anywhere from the coating end position to the winding device 9 . Also, the masking base material 3 may be applied with an adhesive or a pressure-sensitive adhesive on the surface thereof in contact with the electrolyte membrane. Anything that can withstand heating and a solvent atmosphere and that leaves no residue on the electrolyte membrane when peeled off is even better. Also, the adhesive of the masking base material should be formed in a porous form or in the form of thin stripes at intervals so as to be easily peeled off from the electrolyte membrane, and the area of the masking base material should be 2/3 or less, preferably 1/3 or less. Furthermore, since the adhesive is sufficient to prevent displacement, it may be applied spotwise at intervals of 10 to 100 mm in the direction of movement to reduce the adhesive area to 1/100 or less.

FIG. 2 shows the details of the configuration of FIG. The masking substrate may be pre-adhered with tape. The width of the middle masking base material 3' in the three rows of masking base materials 3 is double the width of the masking base materials at both ends to form an uncoated part in the moving direction of the electrodes, and the width of the two uncoated parts is It is possible to manufacture an MEA in which one-sided electrodes or both electrodes are formed on the same periphery.
If it is desired to form three rows of electrodes, four rows of masking members 3 are required. Also, the width of the masking base material near the center may be made wider than the width of the masking base material on both sides, for example, twice in order to make the desired uncoated portion of the MEA.
The coating device 5 can perform continuous or pulsed spray coating while traversing the electrolyte membrane perpendicularly to the advancing direction of the electrolyte membrane. The heated suction roll can stop rotating while traversing and coating. It can be applied in a spray pattern 6 by a single applicator 5 or in a composite pattern by a plurality of applicators. When the electrolyte membrane is continuously moved, the coating distribution can be made uniform by spraying only one side of the reciprocating movement by the traverse device, that is, only the outward movement or only the return movement. In this case, for example, the forward speed of the coating movement is slowed down to, for example, 100 mm/sec or less to increase the coating efficiency, and the return speed of the non-coated pass is doubled to 200 mm/sec or more to increase productivity. Electrode ink is pulse-applied to a substrate (not shown) outside the electrolyte membrane 2, and the coating weight can be measured by moving out of the coating booth and closing the shutter of the coating weight measurement chamber. If the coating weight is not the target coating weight, the number of pulses, ejection time, traverse speed, liquid pressure, etc. can be finely adjusted, but finer adjustment is possible by adjusting the pulse ejection time in increments of 0.01 to 0.1 mm/second. It is easy because it can be weighed each time.

FIG. 3 shows the electrode 10 and the electrode ink uncoated portion 11 (electrolyte membrane) after applying the electrode ink to the electrolyte membrane and removing the masking member.

FIG. 4 adds a second masking substrate 12 positioned orthogonal to the moving electrolyte membrane in FIG. The second masking base material 12 moves under the coating device 6 at the timing of providing an uncoated portion of the electrolyte membrane. The electrode ink may be sprayed onto a first masking substrate in the direction of electrolyte migration to produce a square pattern, and only the second masking substrate may be used to apply the electrode ink to the electrolyte with slot nozzles. The film is applied in a sharp direction, and when the electrode ink starts to be applied at low pressure, the flow rate is high and the pattern spreads like a hammer. By eliminating the influence or similarly finishing the coating on the second masking base material, the electrode ink can be uniformly coated and the electrodes can be formed.

In FIG. 5, the second masking substrate 12 is moved at desired timing. The electrode ink applied on the second masking base material by the coating device 5 is unwound by the unwinding device 15 of the second masking base material 12 for each desired number of coatings or time, and is automatically wound by the winding device 16. , the electrode ink can be rolled up to a certain thickness on the second masking substrate.

FIG. 6 shows an application type of FIG. 5 in which the unwinding device 15 and the winding device 16 for the second masking base material are on one side and are wound via a free roll 30 and a guide roll 31 connected by a bracket or the like (not shown). can be done.

FIG. 7 shows an electrode 10 formed by a composite of a first masking base material and a second masking base material on an electrolyte membrane 2, and an uncoated part 11. The uncoated part is cut to form a peripheral edge 11. It is formed.

FIG. 8 shows a configuration in which a masking film is laminated on the electrolyte membrane 2 laminated on the back sheet 17. In this configuration, the first electrode ink is applied by being adsorbed by the heating adsorption roll.

In FIG. 9, the masking base material 3 is laminated on the electrolyte membrane on which the first electrode is formed, and the support base material 18 is laminated on the first electrode side. An adhesive 19 is applied to both sides of the support base material 18, and the adhesive 19 and the electrolyte membrane are in contact with each other. The support substrate is preferably a breathable substrate such as a porous film or dust-free paper because it can adsorb the uncoated portions of the electrolyte membrane and the electrodes, thereby preventing deformation of the electrolyte membrane when the second electrode ink is applied. It is desirable that the air-permeable film and dust-free paper have a size and structure that allow air to pass through so that particles do not migrate to carbon on which platinum or the like of the electrode is supported. By using a breathable film or a commercially available dust-free paper, the suction hole diameter of the heating suction drum can be 0.1 mm to 0.6 mm, the pitch is 0.7 mm to 2 mm in a staggered pattern, and a vacuum pump with a degree of vacuum of 60 to 100 KPa is used. A sufficient adsorption effect is obtained by using the electrode ink, and the electrolyte membrane is not deformed by applying the electrode ink to the electrolyte membrane heated to about 50 to 80.degree.

FIG. 10 is a view showing the manufacturing of MEA 20 by forming a first electrode 10, a second electrode 10', and uncoated portions on both sides of an electrolyte membrane 2 according to the present invention, and cutting the uncoated portions.

FIG. 11 shows the arrangement of three heads 5-a, 5-b, and 5-c that move and spray perpendicularly to the advancing direction of the electrolyte membrane. The number of coating heads may be one, or five or more. Production speed can be increased by increasing the number of heads for a given spray pattern size. When multiple heads are used, it is important to arrange them so that the spray streams do not interfere with each other in order to achieve uniform coating.

FIG. 12 shows spray coating patterns 41, 42 and 43 directly under the three heads. The patterns are arranged so as not to interfere with each other.

In FIG. 13, when the three heads reciprocate perpendicularly to the moving direction of the electrolyte membrane to perform spraying, the coating timing is controlled so that the coating patterns are aligned in the moving direction of the electrolyte membrane. From the viewpoint of overcoating, it is better to arrange the respective heads so that the coating patterns 41, 42, and 43 are slightly overlapped.

In FIG. 14, the pulsating patterns 41, 42 and 43 in the moving direction of the head are sprayed from each head in the forward movement of the spray head, and the pulsating patterns 41, 42 and 43 are sufficiently overlapped. During forward movement, the electrolyte membrane and the heating adsorption roll (not shown) are stopped.

FIG. 15 shows offset movement of the electrolyte membrane together with the heated adsorption rolls to sufficiently wrap the patterns 41, 42, 43 in the backward movement. For example, when the width of each pattern is 20 mm, the offset is moved by 10 mm, and when the width is 30 mm, the offset is moved by 15 mm.
When each pattern is 20 mm, for example, when the spraying of the next forward movement is started, the electrolyte film is moved by 50 mm, which is the total of 60 mm of the control pattern of the three heads minus the half pattern of 10 mm, and the electrolyte membrane is moved together with the heating adsorption roll to achieve uniformity. Electrodes can be formed.

In FIG. 16, the masking base material 3 is laminated on both sides of the electrolyte membrane 2 . The electrode ink is sprayed in pulses. In order to make the coating amount of the electrode ink near the periphery uniform, it is preferable that more than half of the spray pattern adheres to the masking base material. It is also possible to reduce the coating amount in the vicinity of the periphery so that the pattern hardly adheres to the masking substrate.

FIG. 17 shows a configuration in which the pulsating spray of FIG. 16 can be continuously sprayed. The merit of the continuous spray is that the reciprocating speed of 50 to 100 mm/sec of the pulse spray can be increased by, for example, 1.5 to 10 times, so that the throughput of electrode formation can be increased. However, the faster the speed, the more the spray flow is swayed by the moving wind, and the coating efficiency is drastically reduced.

According to the present invention, a membrane-electrode assembly (MEA) for a PEFC fuel cell with a peripheral edge can be manufactured, and it can be manufactured with high quality because it is performed by the CCM method in which electrode ink is directly applied to the electrolytic membrane and dried to form an electrode.

Reference Signs List 1 heating adsorption roll 2 electrolyte membrane 3 first masking substrate 4 electrolyte membrane with electrodes 5 coating device
6 Spray flow 7 Guide roll 8 Electrolyte membrane unwinding device 9 Electrolyte membrane winding device
10 first electrode 10' second electrode 11 electrode ink uncoated portion (periphery)
12 second (perpendicular) masking substrate 15 second masking substrate unwinding device 16 second masking member winding device 17 backsheet 18 support substrate (breathable substrate)
19 adhesive 20 membrane electrode assembly (MEA)
30 free roll 31 guide roll 41, 42, 43 spray pattern

Claims (7)

A method for manufacturing a fuel cell comprising a membrane electrode assembly in which an electrode ink is directly applied to one side of an electrolyte membrane by a coating device and dried to form an electrode, and an opposite electrode is formed on the opposite side of the electrolyte membrane, wherein the electrolyte is A step of arranging a plurality of spray coating devices that move perpendicular to the moving direction of the film, a step of arranging a plurality of rows of coating devices in front and behind the moving direction of the spray coating devices and spraying, and a step of spraying in one row. The step of installing the spray pattern so that it is applied in another row between the trajectories of the spray pattern, and the movement of the spray coating device perpendicular to the moving direction of the electrolyte membrane are offset while moving, and continuous spray or pulsed spray is performed. Manufacture of a fuel cell characterized by using a membrane electrode assembly in which the spray pattern is laminated a plurality of times, and at least one electrode of the electrolyte membrane forms a peripheral edge consisting of the electrode and the uncoated portion with a mask. Method. A fuel cell comprising a membrane electrode assembly in which electrodes are formed on both sides of an electrolyte membrane, wherein the electrolyte membrane is heated and adsorbed, and the electrode ink is applied directly to at least one side of the electrolyte membrane by continuous spray coating or pulsed spray coating. and forming at least mesopores in the electrode even if the solvent of the applied electrode ink is instantly volatilized. 10 to 25 application heads are arranged in one or two horizontal rows perpendicular to the movement direction of the long electrolyte membrane, and the application heads are short traversed to wrap the spray pattern in a pulsed manner to form the membrane electrode assembly. A method for manufacturing a fuel cell, characterized by using: A method for manufacturing a membrane electrode assembly in which electrodes are formed on both sides of an electrolyte membrane, comprising a step of heating and adsorbing the electrolyte membrane, and a continuous spray coating method or an impact pulse spray method to spray particles onto the electrolyte membrane with speed. and forming at least mesopores in the electrode by laminating a plurality of layers by instantly volatilizing the solvent of the electrode ink after coating to offset the spray coating. manufacturing method. A membrane electrode assembly in which electrodes are formed on both sides of an electrolyte membrane, the electrolyte membrane is heated and adsorbed to move, and the electrode ink is applied to at least one side of the electrolyte membrane by a plurality of rows of a plurality of spray coating devices to move the electrolyte membrane. It moves perpendicular to the direction and is applied to the electrolyte membrane with speed by a continuous spray method or an impact pulse spray method. A membrane electrode assembly characterized by forming at least mesopores in an electrode by laminating layers. Electrodes are formed on both sides of a long electrolyte membrane, and at least one side is formed with a plurality of electrodes and an uncoated portion outside the electrodes by a mask, and the electrolyte membrane uncoated portion is applied to the air-permeable substrate. A composite of a membrane electrode assembly and an air-permeable substrate, in which a peelable pressure-sensitive adhesive or adhesive is laminated. A fuel cell comprising a membrane electrode assembly in which electrodes are formed on both sides of an electrolyte membrane, wherein the electrolyte membrane is heated and adsorbed and moved, and electrode ink is applied to at least one side of the electrolyte membrane by a plurality of rows of spray coating devices. The electrode ink is applied to the electrolyte membrane with speed by a continuous spray coating method or an impact pulse spray method, moving perpendicular to the moving direction of the membrane, and instantaneously volatilizing the solvent of the electrode ink, drying, and repeating lamination. 1. A fuel cell comprising a membrane electrode assembly in which micropores and mesopores are formed in an electrode by laminating a plurality of layers.

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